This invention refers to an inexpensive, zero leakage path, low differential pressure seal for a piston-cylinder arrangement. More specifically it refers to a low speed or high speed reciprocating piston-cylinder zero leakage path seal for fluid compressors, fluid motors, fluid pumps and internal combustion engines.
It is known from prior art to obtain zero leakage path in a piston-cylinder arrangement use of an "O" ring seal, lip seal, or the like is used. However, present technology limits their use to slow speed reciprocating piston-cylinder configurations.
Present technology for high speed reciprocating piston-cylinder configurations is based on controlled and or minimal leakage seal of the fluid past a split ring set into a groove of a piston reciprocating in a cylinder.
I have invented an art with a zero leakage path which becomes more positive with the more pressure it is subjected to. Prior art has leakage increasing with fluid pressure acting on the seal, whereas, this invention becomes a more positive seal the more fluid pressue it is subject to, and since there is no leakage path, any leakage encountered is from the cylinder well and the ring face imperfections of the various sealing surfaces.
Prior art has two basic losses associated with it. The first being the friction loss of the ring scraping against the cylinder wall. This friction is caused by the designed radial tension in the ring to seal said pressurized fluid and additional radial tension put on the ring by the pressurized fluid itself. This friction loss increases as the face width of the ring increases. The ring face width is dependent upon the pressure and more specifically the temperature variations of the pressurized fluid and the configurations of the face proper which causes for width. As pressurized fluid temperatures increase the ring face width increases to avoid burn-thru (i.e. the Challenger effect). As ring face width increases friction increases between the ring and cylinder. Yet, functionability of the art requires the friction loss to properly seal.
Prior art minimized pressurized fluid leakage by increasing the number of rings used, special design considerations to the outside diameter face of the rings, ring juncture design enhancements, etc. Increasing the number of rings to stop pressurized fluid leakage and/or scrape oil increases the frictional loss. However, all prior art reduces but does not eliminate total leakage paths. Leakage occurs past the face of the ring against the cylinder wall as detailed above, thru the juncture of the gap of the ring ends, and behind the ring and its groove. Additionally, in four cycle internal combustion engines the compression rings axial movement, though ever so minute, acts as a pump of the crankcase under the ring and oil into the combustion chamber.
The second loss associated with prior art is the actual leakage associated with the piston-ring-cylinder seal. Assuming there is no leakage by the face of the ring and the cylinder due to prior art considerations as mentioned then leakage loss occurs thru the gap associated with the ends of the ring. Likewise, said gap leakage is very dependent upon the temperature and pressure of the fluid. Additionally, another leakage loss occurs in a path behind the ring and its respective groove.
This invention stops the leakage behind the ring and its groove and thru the ring gap. When said leakage is inhibited then at higher temperature applications of the pressurized fluid the "hot spot burn thru" (Challenger effect) is also eliminated thus reducing the ring face thicknesss to mechanical considerations only.
The result being a sizable reduction in frictional loss of ring-cylinder friction since only one new art ring is required and a sizable gain in efficiency from increased compression of same due to essentially zero blow-by.
Using this new art on a pressurized liquid fluid application a sustained vacuum draw of 27 inches of mercury is demonstrated repeatedly over a sustained period with high usage of the new art seal. Said seal dimensional characteristics of the ring, ring groove, and the cylinder are considered extremely loose compared to prior art requirements and manufacturing capabilities.
Likewise, applying the new art to internal combustion engines has resulted in the use of only one new art ring versus two or more compression rings in typical two cycle internal combustion engines. Tests show a considerable horse power and compression increase in said engine due to reduced ring friction (via reduction in ring face width and number of rings) and near zero blow-by, thereby increasing horse power availability for the same amount of gas consumed. These results were observed in two cycle engines of size varying from single piston air cooled to a large industrial six cylinder water cooled diesel engine.
The same results as observed in the two cycle internal combustion engine were observed in four cycle engines plus additional considerations. As in the two cycle engine, the four cycle application of the new art required only one compression ring versus two rings required in prior art. Additionally, prior art necessitated an oil wipe ring for four cycle engines. The new art does not need such a ring.
Tests show that the new art single ring facilitates and improves the function that in prior art, two compression rings are required to accomplish on four cycle engines. Also, the new art eliminates pumping of crankcase oil by axial movement of prior art rings either thru the gap and or behind the prior art rings. Additionally, because of even and floating radial loading of the new art ring, it wipes crankcase oil off the cylinder wall with no leakage thru a gap or behind the ring for there is no passage. Hence, the new art eliminates the need for an oil wipe ring on four cycle engines.
With the elimination of the need for a second (or more) compression ring in two cycle internal combustion engine and the elimination of the need for a second compression ring and oil wipe ring used in standard practice in a four cycle internal combustion engine, the opportunity exists to move the wrist pin closer to the crown of a piston with many associated advantages such as, horse power, compression, efficiency, weight, mass, volume, etc.
Prior art, be it for internal combustion engines, pumps, motor, compressors, etc. for high speed reciprocating piston-piston ring-cylinder configurations have the piston centered in the cylinder by the piston skirt. This prior art configuration necessitated a specific length of skirt in addition to skirt lengths required for compression ring(s), oil wipe ring and wrist pin. The quantity of specific rings needed being dictated by the application.
Prior art rings could be floating to an axis of the cylinder which is different than the axis of the piston skirt. Thus, causing for increased friction and blow-by all causing an efficiency loss.
The new art has the single ring centering the piston head within the cylinder. Hence, the piston and piston ring are on the same cylinder axis regardless how much said axis varies in its length.
The new art allows for oval, square, rectangular piston-piston ring-cylinder configurations.
Additionally, it has been observed that in internal combusion engines that with zero blow-by choking is no longer required or vastly reduced because the charge is being maintained in the cylinder it gives the engine immediate starting capabilities.
Prior art for high speed reciprocating piston cylinder arrangements have a paradox of:
If thermal expansion is not detrimental, then a gapless ring is possible. However, friction wear and no gap are causes for ring face blow-by.
If thermal expansion requires a gap in the ring, then blow-by is present initially. The new technology is self-adjusting in either of the aforementioned paradoxes.
Prior art requires the piston rings to be made of material with radial elasticity for sealing considerations. This necessity eliminated materials with optimun temperature, weight, durability, etc. characteristics from consideration as ring material. The new art technology accepts sealing band materials with no radial elasticity, but doesn't require same for Radial elasticity is provided by the new art seal expander. The drawings show the ring groove perpendicular to the piston and/or cylinder centerline. It is realized it may be desirable for manufacturing, or oil scraping from cylinder walls in four-cycle internal combustion engines, and/or ring sliding over cylinder ports in two-cycle internal combustion engines to angle the ring groove of the piston relative to the cylinder wall or passage centerline to meet specific requirements.
In accordance with certain of its objects, my invention relates to a sealing assembly for internal combustion engines, compressors, fluid motors, fluid pumps and other devices which require sealing which comprises: an assembly of members to be sealed, one member axially centered over another member with a clearance passage between the assembled members, capable of allowing the assembly of members to move in relation to one and the other; said clearance passage being capable of transmitting a fluid under pressure; one of the members having one or more grooved openings to the clearance passage between the assembly of members, said groove openings having side walls and a bottom; positioned within and at the bottom of said groove openings is a continuous, resilient, elasteromeric, expander seal; positioned with said groove openings and biased to said expander seal is one or more gapped sealing bands. The one or more sealing bands have an inclined surface that engages the expander seal and said incline surface is in the direction of a fluid source under pressure; a means for actuating the fluid under pressure whereby the fluid under pressure engages the one or more sealing bands and engages and activates the expander seal causing said expander seal to pressurize and expand against the inclined surface of the one or more sealing bands thereby forcing said one or more sealing bands against the ungrooved member and against wall of said groove opening thereby causing a seal.
Further, in accordance with certain of its objects, my invention relates to a sealing assembly for internal combustion engines, compressors, fluid motors, fluid pumps and other devices which require sealing which comprises: an assembly of members to be sealed, one member axially centered over another member with a clearance passage between the assembled members, capable of allowing the assembly of members to move in relation to one and the other; said clearance passage being capable of transmitting a fluid under pressure; one of the members having one or more grooved openings to the clearance passage between the assembly of members, said groove openings having side walls and a bottom; positioned within and at the bottom of said groove openings is a continuous, resilient, elasteromeric, expander seal; positioned within said groove openings and biased to said expander seal is one or more gapped sealing bands; the one or more sealing bands have a flat surface that engages the expander seal and an axial porous force which engages the one or more sealing bands and engages the side wall of the groove opening, said groove wall in the direction of a fluid source thus pushing the one or more sealing bands against the other groove wall; a means for actuating the fluid under pressure whereby the fluid under pressure engages the one or more sealing bands and engages and activates the expander seal causing said expander seal to pressurize and expand against the flat surface of the one or more sealing bands thereby forcing said one or more sealing bands against the ungrooved member and against the wall of said groove opening thereby causing a seal.
Still further, in accordance with certain of its objects, my invention further relates to a sealing assembly for fluid cylinders, internal combustion engines, compressors, fluid motors, fluid pumps and other devices which require sealing which comprises: an assembly of members to be sealed, one member axially centered over another member with a clearance passage between the assembled members, capable of allowing the assembly of members to move in relation to one and the other; said clearance passage being capable of transmitting a fluid under pressure; one of the members having one or more grooved openings to the clearance passage between the assembly of members, said groove openings having side walls and a bottom; positioned within and at the bottom of said groove openings is a continuous, resilient, elasteromeric, expander seal; positioned within said groove openings and biased to said expander seal is one or more gapped sealing bands; the one of more sealing bands have a flat surface that engages the expander seal and an axial porous force which engages the one or more sealing bands and engages one side wall of the groove opening, thus pushing the one or more sealing bands against the other groove wall, both groove walls having serrations and/or protrusions allowing fluid passage; a means for actuating the fluid under pressure bi-directionally whereby the fluid under pressure engages the one or more bands and engages and activates the expander seal causing said expander seal to pressurize and expand against the flat surface of the one or more sealing bands thereby forcing said one or more sealing bands against the ungrooved member and either against one wall of said groove opening thereby causing a seal, or against the force which is against said groove opening thereby causing a seal.